Six years ago, FBI agent Malcolm Turner (Lawrence) went deep undercover, donning a body suit and floral tent dresses to impersonate a buxom septuagenarian and capture a bank robber.

When national security is threatened again, this time by a computer worm created by programmer Tom Fuller (Moses), Malcolm dusts off his gravity-defying disguise to take up the position of nanny in the Fuller household.

Big Momma immediately endears herself to Tom's control freak wife Leah (Procter), toddler Andrew (Trevor and Preston Shores), who enjoys flinging himself off the furniture, and youngest daughter Carrie (Moretz). Eldest daughter Molly (Dennings), who is going through a Goth phase, is rather less impressed.

As Malcolm edges closer to cracking the case, he finds his loyalties torn between his job and genuine affection for the enterprising youngsters in his care. …